This invention relates to an alarm clock and more particularly to an alarm clock of the type wherein an alarm device is actuated at the simultaneous synchronization of phases of an hour unit gear and a minute unit gear, both provided for indicating time, with a preset alarm signaling time.
In a conventional alarm clock the usual method of actuating an alarm signaling device is to merely detect a phase of an hour unit gear, however, the method has the disadvantage that the alarm signaling time often deviates widely from a preset alarm signaling time due to the very slow rotation of the hour unit gear.
Another disadvantage of the conventional alarm clock, most of which are analog clocks, is that an alarm signaling time is rarely preset to the accuracy of a minute because of analog presetting of the alarm signaling time.
In order to overcome these disadvantages improvements have been made in which the preset alarm signaling time is indicated in digital values. However, the resulting improvements are unsatisfactory, because although the preset alarm signaling time is indicated to an accuracy of a minute, the alarm signaling time still deviates widely from the preset time as the detection of synchronization is performed only with respect to the hour unit gear as in the conventional method.